The need for higher speeding system is increasing particularly with the development of more sophisticated networks, multimedia applications and high speed communications. The requirements are such that today 100 Gigabit/s switches will be more and more needed. However, a first problem comes from the fact that the speed of the switch is strongly dependent on the actual technology that is used. Therefore, for a defined state of the technology it seems difficult to achieve the possibility of enhancing the switches that are known. There is therefore a need for aggregating elementary switching module in such a way that still preserves the internal capabilities and efficiency of the module. Particularly, it is essential that the combination of the switching structure does not require input or output ports for performing the arrangement, thus decreasing the number of ports that remains for the customer. Additionally, it is necessary that the aggregate switching system remain in single stage.
A second problem arises from the fact that the customers' premises are equipped with line attachments that are fixed and determined for a relatively long period of time, at least since the investments being performed for the telecommunications equipments can not be drastically lost. Therefore, although there is a strong need for higher speed switching systems, there is a desire for preserving the investments that were already made and thus for permitting a wide range of attachments.
Additionally, the switching system should be adapted to ATM telecommunication links and provide wide multicasting capabilities (that is to say the possibility of duplicating the cell being entered into the switch so that the latter can be duplicated at different output ports), and should permit the different line attachments to be achieved in different physical areas.